1. Technical Field
The present invention relates to a liquid discharging apparatus that transfers a liquid discharging head relative to a workpiece so as to perform a drawing on the workpiece, and more particularly, to a liquid discharging apparatus, which includes maintainers for performing maintenance, such as cleaning, of a liquid discharging head, and a method of performing maintenance on a liquid discharging head.
2. Related Art
An inkjet liquid discharging apparatus in the related art has been known as an apparatus for discharging liquid droplets on the workpiece. For example, such a liquid discharging apparatus is disclosed in JP-A-10-206624 (claim 4, FIG. 1), JP-A-2001-171135 (claim 4, FIG. 1), JP-A-2003-48312 (claim 6, FIG. 1), and JP-A-2003-230858 (claim 3, FIG. 1). The liquid discharging apparatus includes a slide table and an inkjet head (liquid discharging head), and discharge liquid droplets on a workpiece. The workpiece such as a substrate is laid on the slide table, and is transferred in one direction by the slide table. The inkjet head is provided above the slide table, and moves along the guide rail in the direction orthogonal to the moving direction of the slide table.
The liquid discharging apparatus is provided with cleaning devices to cope with the clogging of nozzle of the inkjet head, attachment of dust on the surface of the head, and air bubbles mixed in the liquid in the head. A wiper that wipes the contaminant caused by drying and solidification of a blot on the head nozzle face and liquid, a flusher that discharges air bubbles or thickened liquid in the liquid discharging head, and a capper that caps the surface of the head to intercept air and thus prevents the liquid in the nozzles from being dried, are used as the cleaning devices.
The cleaning devices have been provided so as to be positioned at a side position of the slide table below the guide rail of the inkjet head (JP-A-10-206624 (claim 4, FIG. 1)), so as to be movable along the rail of the slide table (JP-A-2001-171135 (claim 4, FIG. 1), JP-A-2003-48312 (claim 6, FIG. 1)), and so as to be mounted on the slide table (JP-A-2003-230858 (claim 3, FIG. 1)).
However, in the liquid discharging apparatus disclosed in JP-A-10-206624 (claim 4, FIG. 1), during the scanning when the liquid droplets are discharged from the liquid discharging head to perform a drawing, the cleaning device is provided on the outside of the maximum scanning range (drawing range) in which the carriage can move. Accordingly, the carriage should be transferred to a position over the maximum scanning range in order to transfer the liquid discharging head to a position corresponding to the cleaning device. As a result, the guide rail for guiding the carriage is made relatively long so that the carriage can move the position over the maximum scanning range. For this reason, as a length of the guide rail becomes long, there have been problems in that the size of the liquid discharging apparatus becomes larger and the guide rail is easily bent due to the increase in length. Accordingly, the positional accuracy of the liquid droplets (liquid droplet discharge positional accuracy), which are discharged from the liquid discharging head on the workpiece such as a substrate, deteriorates. In particular, as the size of the workpiece such as a substrate is increased, the maximum scanning range becomes larger. Accordingly, the length of the guide rail should become longer. Furthermore, if the weight of the carriage is increased by mounting auxiliary units such as a camera and a measuring device, the guide rail is more easily bent, whereby the liquid droplet discharge positional accuracy further deteriorates.
In addition, in the liquid discharging apparatus disclosed in JP-A-2001-171135 (claim 4, FIG. 1) and JP-A-2003-48312 (claim 6, FIG. 1) in which another moving table is mounted on the rail of the slide table and maintainers are mounted on the another moving table, the maintainers are provided on the outside of a moving range of the slide table, which is required to perform a drawing on the workpiece. Accordingly, the size of the liquid discharging apparatus is increased in the table moving direction.
Furthermore, in the liquid discharging apparatus disclosed in JP-A-2003-230858 (claim 3, FIG. 1) in which the cleaning device is mounted on the slide table, since it is necessary to secure a space for mounting the cleaning device as well as region for laying a substrate on the slide table, the size of the slide table is increased in the table moving direction by the space for mounting the cleaning device. Even in this case, there has been a problem that the size of the liquid discharging apparatus is increased in the table moving direction.